Set of Telecommunication Channels, Apparatus and Process for Multichannel Telecommunication

The present invention relates to a set of telecommunication channels, an apparatus and a process for multi-channel telecommunications.

The invention was made with reference to both analog and digital telecommunications.

Said telecommunication is at least of transmission and reception, but two-way communication is not excluded.

The invention was made with particular reference to the field of wireless transmissions, e.g. radio, however other types of transmission are not excluded.

The invention was made in reference to both a single-user and multi-user transmission.

In the telecommunication sector, there has always been a pressing problem of increasing data transfer capacity.

In general, channels are known as defined each by an electromagnetic wave with a different frequency.

Professor Fabrizio Tamburini, one of the inventors of the present invention, however, has in the past experimented with the possibility of transmitting several channels in the same frequency.

The experiment is known as the “San Marco” experiment as it took place in St. Mark's Square in Venice on Jun. 24, 2011.

During the experiment, an ordinary electromagnetic wave was transmitted at the same time as a twisted electromagnetic wave, i.e., carrying orbital angular momentum, also called OAM, and both were transmitted in the same frequency and modulated to carry the same information (a video signal).

It was found that the waves remained distinct and it was possible to switch from receiving one to receiving the other and vice versa, thus concluding that each could define an independent communication channel in the same frequency. This certainly serves the primary purpose of increasing the data transfer capacity in the same frequency, even possibly multi-user, exploiting one channel for each user.

In addition to the problem of increasing the data transfer channels, there is also the pressing problem of ensuring the quality of the data transmitted, limiting or eliminating the phenomena of uncontrolled interference.

The inventors, following the San Marco experiment, continued their studies in the direction of further increasing the number of channels suited to transfer data with a high-quality standard.

The purpose of the present invention is to overcome all or part of the problems of the known technique.

In particular, a preferred purpose of the present invention is to enable high multi-channel data transmission with high quality.

A preferred purpose of the present invention is to define a plurality of channels in the same frequency, each with a high transmission quality.

Another further preferred purpose is to define a plurality of transmission channels that can also be used for transmission in deliberately disturbed conditions for protective purposes, generally called jamming conditions.

Another further preferred purpose is to define a data transmission that is easily and clearly distinguishable by a predestined receiver within a deliberately disturbed communication for protective purposes (jamming conditions).

The purposes are achieved by the invention as defined in the attached claims, which are incorporated as an integral part of this description.

11 12 1 1 1 1 1 said orbital angular momentum (OAM) of said first wave (W); 1 1 one of said sectors (S. . . . Sp) of said first wave (W) in which said wave is modulated differently from the other sectors. In particular, according to its first general aspect, the present invention concerns a set of telecommunication channels comprising a plurality of first channels (CH, CH) in the same carrier frequency, the set including at least one first carrier electromagnetic wave carrying orbital angular momentum (OAM), i.e., the phase twisted around a with predetermined direction in space (W) characterized by an orbital angular momentum (OAM), OAM for the sake of brevity, the wavefront of said wave being divided in space into sectors (S. . . . Sp) distinct from each other (i.e., not overlapping), where each of said first channels is characterized by:

We note that, for the purposes of the present invention, the carrier frequency of a channel is always considered to be the same even if the wave is frequency modulated within a predetermined bandwidth. In other words, the carrier frequency of the channel has a predetermined frequency modulation tolerance given by the predetermined bandwidth.

2 102 3 103 2 102 1 a plurality of transmitting antennas (T-Tn); 1 a plurality of modulation sections (S-Sp) each defined by a group of said antennas operationally associated with each other; 10 1 1 1 piloting means (), configured to drive said T-Tn antennas to generate at least one carrier electromagnetic wave with the phase twisted around a predetermined direction in space (W) characterized by an orbital angular momentum (OAM) and by a carrier frequency; 11 1 1 11 12 21 22 modulation means (), operationally associated with said sections (S-Sp) to modulate corresponding sectors of the front of said electromagnetic wave (W) with orbital momentum angular (OAM), where the modulations of sectors are independent of each other and define respective channels (Ch, Ch, Ch, Ch) in the same carrier frequency. the Tx transmission device (,) comprises: According to a second aspect, the invention concerns a multi-channel telecommunications apparatus comprising at least one radio transmitting device (,), hereinafter referred to as Tx for brevity, and a radio receiving device (,), hereinafter referred to as Rx for brevity, characterized by the fact that:

1 1 generating at least one carrier electromagnetic wave carrying orbital angular momentum (OAM), i.e., with the phase twisted around a predetermined direction in space (W) characterized by an orbital angular momentum (OAM) and by a carrier frequency; 1 dividing the wavefront into sectors (S-Sp) modulated independently of each other and considering each one as a transmission channel (Chx, x) in said carrier frequency; receiving the wavefront and discriminating said channels. According to a third aspect, the invention relates to a multi-channel telecommunications process comprising the following steps:

1 FIG. 1 With reference to, a first radio telecommunication apparatus is represented according to the present invention, indicated as a whole by reference number.

2 3 Said apparatus s at least one radio transmitting device, hereinafter referred to as Tx for brevity, and one radio receiving device, hereinafter referred to as Rx for brevity.

1 Apparatusdefines between Rx and Tx a set of telecommunication channels having in common the same frequency and the fact that they are defined by an electromagnetic wave in a carrier frequency with the phase twisted around a predetermined direction in space, hereinafter referred to as twisted wave or carrier wave for brevity.

1 FIG. 1 1 1 2 1 the same carrier electromagnetic wave W; 1 1 the same angular momentum OAMof said wave W. in particular shows a plurality of first telecommunication channels Ch,and Ch,, which have in common:

1 1 Said channels are distinct from each other in that each corresponds to a respective sector S-Sp of the wavefront of said twisted carrier electromagnetic wave W.

1 In each sector, wave Wis modulated differently than in the other sectors. Said modulation is preferably in at least one of the following: phase, amplitude, polarization, frequency, path diversity, and other known methods.

Frequency modulation is intended as a modulation of the carrier frequency within a predetermined bandwidth, in which case for the purposes of the present invention the corresponding channels are considered carrier frequency channels. In general, the carrier frequency is preferably in the order of MHz, while the modulation bandwidth is in the order of magnitude of KHz. For example, for a carrier frequency of 88.8 MHz the modulation bandwidth can be +/−100 KHz.

In general, the bandwidth is therefore preferably a fraction of the frequency of the carrier wave (or, in jargon, of the “carrier”).

The channels are centered on the carrier wave frequency, where an FM radio “tunes in” for example; the frequency modulation does not appreciably change the OAM, as those of digital and phase modulations such multiplexing (MUX) like PSK, QPSK, QAM and so on, such as digital TV MUXes for example, are a small perturbation in phase (a controlled ripple) on the fusillo azimuthal phase typical of each of the OAM states. Each channel in that chosen OAM state acts as a “phase carrier” on a channel characterized by a carrier frequency.

To sum up, we therefore have the possibility to make a frequency modulation on the carrier frequency and a phase modulation on the carrier phase shape characteristic of each OAM state. Each OAM state obviously has its own phase imprint which is like a 1-layer spiral, with OAM 1=+1 if levorotatory or 1=−1 if dextrorotatory or with 2 or more layers, ideally up to spirals with infinite layers. A non-limiting figurative example is fusilli, i.e., the well-known pasta shape.

1 a plurality of T-Tn transmission antennas; 1 a plurality of S-Sp modulation sections, each defined by a group said antennas operationally of associated with each other; 10 1 1 piloting means, configured to drive said T-Tn antennas to generate at least one electromagnetic wave, preferably a plurality of them (W-Wk), with respective desired and distinct angular orbital momenta (OAM) for each wave; 11 1 modulation means, operationally associated with said sections (S-Sp) to modulate corresponding sectors of the fronts of said electromagnetic waves with orbital angular momentum (OAM), where the modulations of the sectors of each wave are independent of each other. The Tx transmission device in general includes:

In this way, every single electromagnetic wave with OAM is used as the main signal carrier and each sector of each of these waves corresponds to a channel.

10 Preferably the piloting meansmodulate in at least one of the following: amplitude, frequency, path diversity and phase.

11 Preferably, the modulation meansmodulate in at least one of the following: amplitude, frequency, path diversity and phase.

As a practical figurative example, we can imagine a parallel with a well-known pasta shape. Let's imagine, for example, the spatial structure of the OAM “carrier” as a fusillo (the screw shape of a well-known pasta); we can imagine each fusillo associated with OAM as having lines or small undulations that do not significantly alter its main flap structure, i.e., they always remain fusilli. To have an OAM channel, we need a fusillo with a number of flaps equal to the OAM L value, therefore the structure must be maintained, and the various modulations do nothing but add a small structure on top of the main fusillo structure. The modulation in phase can be thought of as a groove in the fusillo, and in amplitude as a variation in the size of the fusillo, but in any case they preserve the average topology of the OAM phase structure.

1 FIG. 1 1 1 1 1 1 1 1 2 1 1 2 1 1 shows the example of a single twisted electromagnetic wave Wwhere the S-Sp sectors of the corresponding wavefront define as many channels Ch,(W/OAM, S) and Ch,(W/OAM, S). Wave Whas orbital angular momentum OAM.

5 FIG. 1 FIG. 1 2 1 2 1 2 1 2 2 1 2 2 1 2 2 2 2 2 shows the general example of two twisted electromagnetic waves W, Wgenerated by the same Tx ofwith respective orbital angular momenta OAMand OAM, where the wavefronts are divided into the same sectors S-Sp. The second wave Wtherefore doubles the number of channels, as it associates the same number of channels of wave Wto its OAM. Additional channels are indicated with Ch,(W/OAM, S) and Ch,(W/OAM, S).

1 a plurality of R-Rm receiving antennas; 20 1 1 2 1 discrimination means (), operationally associated with said receiving antennas and configured to carry out amplitude and phase measurements of the electromagnetic field in correspondence with different reception points (R) in order to acquire first data indicative of the individual discrimination of (DATA) said electromagnetic waves W-Wk and to process them into second data (DATA) indicative of the discrimination in sectors S, . . . . Sp of each wavefront. The Rx receiving device is placed at a distance from Tx and includes:

20 2 3 1 Finally, the discrimination means () are configured to process said second DATAdata in order to obtain third DATAdata that allow to discriminate in different S-Sp sectors of the various wavefronts the Chx, x data transmission channels, if present.

1 FIG. 2 1 shows an example of transmitting devicewhere the T-Tn antennas are arranged to define an (ideal) transmitting surface T and a transmitting direction D orthogonal to it. Such an ideal transmission surface is, for example, a transmission plane. Preferably, the antennas are arranged in a radial pattern around a D axis orthogonal to the transmitting surface. Overall, the wavefront is omnidirectional and is modulated sector by sector. If we need to communicate with an Rx target moving with respect to Tx or in any case towards a predetermined direction, it is the modulation that points or follows the receiver, while the carrier wave remains omnidirectional.

More generally, there can be two cases: in the first case the wave is omnidirectional and therefore the D axis is orthogonal to the propagation plane and the modulation of the omnidirectional carrier wave towards a predetermined Rx receiver is done using part of the antennas. In the second case, the wave is not omnidirectional and propagates from point A to point B. Also in this case it is possible to modulate various sectors independently, for instance like a satellite transmission to different users, which broadcasts to Earth but transmits different channels in different directions always using different modulations along different directions; in this case the D axis coincides with the propagation axis.

1 FIG. 1 In the example in, the receiving antennas R-Rm are arranged as to define an (ideal) receiving surface R intersecting the wavefront and orthogonal to the transmission direction D—this ideal receiving surface is e.g. a receiving plane.

In the following, alternative forms of implementation of the invention will be described, where elements that are the same or similar to the previous ones will be indicated with the same reference numbers, or with the same numbers increased by 100 or multiples thereof.

2 4 6 7 FIGS.-and- 101 1 show an alternative form of implementation of a radio telecommunication system denoted as a whole by reference number, which differs from apparatusdescribed above substantially by a different reciprocal arrangement of the transmitting and receiving antennas.

102 1 In particular, the Txtransmitting device has the T-Tn antennas arranged as to define a transmitting surface T and a transmission direction parallel to said surface, e.g., with a cylindrical or conical wavefront.

103 1 The RXreceiving device has the R-Rm receiving antennas arranged as to envelop the propagation wavefront transmitted by Tx.

1 For example, when said wavefront is cylindrical or conical around said D axis, the receiving antennas R-Rn are arranged in a radial pattern around said axis.

1 For example, the R-Rm receiving antennas can be arranged to define a plurality of receiving surfaces concentric to the D axis.

20 103 For example, the discrimination meansof the Rxdevice can be configured to perform an anamorphic transformation of affine homology of the wavefront propagating with conical or cylindrical symmetry centered on the D axis.

1 101 The two devicesandare able to generate the same channels.

7 1 2 1 2 1 2 1 2 2 1 2 2 1 2 2 2 2 2 2 3 4 FIGS.,and For the sake of completeness, we note that figure shows the generalexample of two twisted electromagnetic waves W, Wgenerated by the same Tx ofwith their respective orbital angular momenta OAMand OAMwhere the wavefronts are divided into the same S-Sp sectors. The second wave Wtherefore doubles the number of channels, as it associates the same number of channels of wave Wto its OAM. Additional channels are indicated with Ch,(W/OAM, S) and Ch,(W/OAM, S).

In general, in practice multiple channels can be advantageously associated with each OAM wave by independently modulating non-overlapping sectors of the wavefront.

1 In other words, the modulation in the S-Sp sectors of the wavefronts of each OAM wave can be considered as a real novelty, which identifies at least one of the Chx, x data channels that are transmitted simultaneously, on the same carrier frequency, in the same OAM mode either in an omnidirectional direction or along one direction, fixed or selectable.

This represents a major element of differentiation with respect to the apparatuses of known art.

1 In the present invention, in general, each twisted OAM electromagnetic wave, received in correspondence with a generic reception plane, is associated with a data channel Chx, x for which the identifying quantity is constituted by the orbital angular momentum OAM of the W-Wk wave itself.

In order to detect the identifying quantity, i.e. the OAM, of a given data channel Chx, x, it is therefore necessary to know the exact rotation value of the wavefront phase of the electromagnetic wave received in correspondence with the reception plane R, and then to perform phase measurements of the electromagnetic field in correspondence with the chosen wavefront sector and on the corresponding receiving surface R.

In practice, only one or more angular sectors of the chosen OAM wave are modulated to communicate with a desired receiver Rx by means of the appropriate selection of some of the antennas that make up the Tx array. Those that are used to communicate toward a chosen Rx receiving user will transmit codes, symbols, or other types of signals modulated on the wave with OAM, while the rest of the antennas can, for example, contribute to jamming by sending random symbols or signals, or communicate with other Rx users.

1 The OAM transmission of the present invention is called “selective” because it preferably activates one or more T-Tn antennas oriented towards one or more Rx receiving devices by means of an electronic feedback (not excluding the mechanical one) which appropriately activates one or more antennas that transmit OAM and directs the desired transmission within certain angular sectors of the omnidirectional beam that identify the directions of the receiving stations (which can in turn be other jamming sources). This system also makes it possible to direct and tighten at will each angular sector (or cone) of communication where the communication modulation takes place. The rest of the wavefront can be a source of jamming, which takes place by means of a modulation to be chosen appropriately.

As is known from the literature, the OAM of an electromagnetic wave is a quantity that uniquely characterizes an azimuthal phase distribution in the wavefront on a plane orthogonal to the propagation of the wave itself and around the propagation axis D of the wave itself.

More precisely, the OAM associated with an electromagnetic wave is characterized by an integer quantity, positive or negative, which expresses the number of complete rotations (i.e. 360 degrees) made in the wavefront within a distance equal to the wavelength in a left- or right-handed sense.

An electromagnetic wave with non-zero OAM has a region in which the electromagnetic field, in a neighborhood of the line coincident with the direction of propagation, also known as the electromagnetic vortex, has an intensity and amplitude close to zero. This phenomenon is due to diffraction effects in the remote transmission of the electromagnetic wave.

Electromagnetic waves with an integer value of OAM have a characteristic intensity structure with an axial symmetry in the form of concentric rings characterized by different values of electromagnetic field intensity on a plane orthogonal (in jargon “doughnut”) to the propagation axis, and a phase structure characterized by a finite number of spirals wrapped along the direction of propagation D and formed by the phase of the wavefront, properties independent, in the far field, from the polarization state of the wave itself (in jargon “fusilli”). In this case, it is said that the electromagnetic wave has a well-defined spatial structure of phase and amplitude that is preserved during propagation in a preferably homogeneous medium.

The present invention associates at least two independent data transmission channels with an electromagnetic wave having a certain carrier frequency and a certain OAM.

The definition of “data transmission channel” (or “data channel”) is used here to indicate a signal that carries information, without any limitation regarding the type of said signal (audio, video, multimedia, digital data exchange, etc.) or the technological method used for its generation and transmission, including for example both analog and digital.

Multi-user omnidirectional distribution using OAM states benefits from the multiplication of the data transmission channels, preferably after a topological transformation of the wavefront that sees as a singularity of coordinates the intersection of the measurement plane (or surface) with the D axis of propagation of the OAM wave transformed into an axis of symmetry coincident with D in a propagation orthogonal to it following the rules of geometric anamorphic transformations of affine homology, as in the case of a directional OAM beam characterized by a doughnut-shaped wavefront with the vortex at the center (which is always characterized by having zero field intensity and is the center of symmetry for any integer value of OAM) when it reflects on the surface of a cone whose axis coincides with the propagation axis of the electromagnetic waves beam (D axis) and is thus reflected omnidirectionally on a plane perpendicular to the D propagation axis.

In the case of a single OAM mode with known symmetry of the field intensity with respect to the D axis on the plane orthogonal to it, the anamorphic transformation of affine homology transforms this figure into a wavefront with conical or preferably cylindrical symmetry, preserving the intensity symmetry of the electromagnetic field and transforming the original “fusilli” spatial phase structure into a spiral centered on D, whose pitch is determined by the phase shift imposed by the value of the OAM itself.

As indicated above, the present invention provides an apparatus and a method for the creation of a radio link that allow each individual OAM channel to be multiplied by dividing the wavefront of each OAM electromagnetic wave into different sectors that share the same carrier, which is modulated independently in amplitude, frequency, polarization, or phase in each of these sectors.

In this way we preserve the physical and structural properties of the original carrier wave, guaranteed by the well-known topological stability of OAM waves during propagation, thus increasing the data transmission capacity of each wave and its stability after propagation by dividing the wavefront into sectors.

The definition of “carrier” or “carrier wave” is used here to indicate a generic electromagnetic wave or electrical signal with known frequency, amplitude, polarization, and phase characteristics, which is modified by a modulating signal, usually containing information, and then transmitted over the air or in other ways used by current art such as for instance fiber, waveguide or cable.

The definition of “sector” is used here to indicate a portion of the wavefront of the OAM electromagnetic wave that preserves its structure during its propagation toward at least one receiving Rx user.

1 1 As mentioned, in general the present invention refers to an apparatusfor creating a radio link with waves propagating along the propagation axis D, and to an configuration of such apparatus where, alternative following an anamorphic transformation of affine homology, the wavefront of such electromagnetic waves propagates with cylindrical or conical symmetry in directions orthogonal to the axis itself. In each of the configurations, the wavefront of the sample electromagnetic wave W is divided in a plurality of example S-Sp in which the wavefront is modulated independently.

1 1 2 1 1 2 2 Apparatusincludes a plurality of transmission antennas T, T, . . . , TN capable of transmitting an electromagnetic wave, W, in OAM mode and characterized by a precise and integer value OAM=11, and at least one other wave Wwith a different value OAM=12, which in this case form a pair of electromagnetic waves.

1 2 1 2 1 2 The OAM value of at least one wave is mandatorily different from 0, but it is not excluded that the antennas can simultaneously generate also “standard” waves with OAM=0, which can be used, for example, as a jamming channel in the same frequency of the other waves. As mentioned, the plurality of antennas T, T, . . . , TN is preferably suited to transmit a set of electromagnetic waves W, W, . . . , Wk with different OAM values and to independently modulate each of the OAM carriers in selected sectors S, S, . . . , Sp of each wavefront.

1 2 The electromagnetic waves W, W, . . . , Wk have the same carrier frequency, preferably in the range between 30 KHz and 300 GHz, and propagate uniformly so that the wavefront propagates along directions orthogonal to a given axis having direction D, or alternatively along the axis itself.

1 1 2 1 2 Preferably, apparatuscomprises a plurality of transmission antennas T, T, . . . , TN arranged on a transmission plane T orthogonal to direction D and suited to transmit the pair of electromagnetic waves W, Walong the propagation directions orthogonal to D.

1 2 1 2 Preferably, the transmitting antennas T, T, . . . , TN are arranged in correspondence with a set of transmission points t, t, . . . , tN belonging to the transmitting surface T.

1 2 Preferably, the transmitting antennas T, T, . . . , IN are positioned along at least one circumference or ellipse lying on said transmitting surface T.

1 2 1 2 The transmission antennas T, T, . . . , TN are preferably arranged on a single circumference or ellipse lying on the transmission plane T and centered on axis D. Some forms of implementation (not illustrated) of the present invention may, however, envisage that the transmitting antennas T, T, . . . , TN be arranged on several concentric (or confocal) circumferences or ellipses on the same plane orthogonal to D or on planes parallel to or sharing a single attachment point on the A axis and open in a radial pattern.

10 1 2 1 2 Preferably, second piloting meanscan be electronic means operationally associated with the transmission antennas T, T, . . . , TN to regulate the transmission of electromagnetic waves W, W.

10 The piloting meanscan include any type of analog or digital circuit, as needed.

1 2 10 1 2 The transmission of electromagnetic waves W, Wcan take place with known multiplexing modalities. For example, the piloting meanscan drive the transmission TN antennas T, T, . . . , TN through corresponding transmission signals, each of which is characterized by a different phase.

1 2 1 2 In this way, the array of transmission antennas T, T, . . . , TN can easily generate electromagnetic waves W, W, . . . , Wk superimposed on each other but characterized by a different orbital angular momentum.

1 FIG. 1 2 Preferably, in the configuration shown in, the axes of the transmitting antennas T, T, . . . , TN are oriented so that they converge at a midpoint between the transmission plane T and the receiving plane R, along the propagation direction D.

2 3 4 FIGS.,and 1 2 Alternatively, in the configuration ofobtained with the anamorphic transformation of affine homology, the axes of the transmitting antennas T, T, . . . , TN are oriented in such a way as to converge at a midpoint of common junction between the transmission plane T and the concentric receiving surface R, in directions orthogonal to the propagation direction D.

1 2 1 101 In some forms of implementation of the present invention, the transmission antennas T, T, . . . , TN may consist of very simple structures, e.g. Yagi-Uda antennas, rotation paraboloids, holes in metal shields or “backfire antennas”, thereby reducing the costs of building the transmission system of apparatuses,.

1 2 Preferably, to further improve their directivity, transmitting antennas T, T, . . . , TN can be made using dielectrics, complex optical schemes, metamaterials and/or plasmonic materials.

10 1 2 Preferably, the piloting meansare able to associate at least one transmission channel Chx, x to the electromagnetic wave Wsuperimposed on waves W, . . . , Wk.

10 To this end, means of encoding, including known ones, can be operationally associated or integrated to/in the piloting meansto transmit data along the Chx, x transmission channel.

11 1 2 Preferably, the modulation meansindependently modulate the wavefronts in the wavefront sectors (S, S, . . . , Sp) using as carrier waves each of the electromagnetic waves with OAM≠0 (i.e., both 0> and 0< are possible).

1 11 Preferably, the regulation means (not illustrated) of the polarization state of electromagnetic waves W-Wk are operationally associated or integrated to/in the modulation means.

In this way, the data transmission channels can be doubled using the degree of freedom offered by polarization.

1 2 1 1 Preferably, the transmitting antennas T, T, . . . . TN are able to transmit multiple electromagnetic waves W-Wk and to associate each electromagnetic wave to at least one different transmission channel Chx, x for each S-Sp sector of the wavefront.

3 103 1 2 1 1 2 1 2 The receiving device,in general comprises a plurality of receiving antennas R, R, . . . , RM capable of simultaneously receiving a W, W, . . . , Wk set of these electromagnetic waves superimposed on each other. The W, W, . . . , Wk set of electromagnetic waves is preferably used for the transport at a distance of k*P different signals of data channels (where k is the number of waves and P the number of sectors of each wavefront) with carriers P, P, . . . , Pk respectively associated with them.

1 2 1 2 1 2 1 2 The electromagnetic waves W, W, . . . , Wk are characterized, respectively, by different orbital angular momenta, e.g., a first and second orbital angular momentum m, m, . . . , mk, where m, m, . . . , mk are different integers, positive or negative. Possibly, one of the electromagnetic waves W, W, . . . , Wk can have zero orbital angular momentum (in this case it is not a twisted wave but it can still be used for example for jamming modulation).

1 2 1 2 1 2 The carriers P, P, . . . , Pk of each of the electromagnetic waves W, W, . . . , Wk can be modulated separately and independently in different sectors S, S, . . . , Sp, to increase the capacity of each wave by at least p times the capacity compared to a channel exploiting the entire wavefront. Each of the Sj sectors, 1≤j≤p, can be advantageously used as an independent data channel to distribute information along a given direction toward different users.

1 FIG. 1 2 1 2 As schematically illustrated in, on the path to the receiving antennas R, R, . . . , RM the wavefront of each of the electromagnetic waves W, W, . . . , Wk rotates around the propagation axis D, on the generic plane orthogonal to this direction of propagation. The electric field of each of the electromagnetic waves thus draws a set of helical trajectories in space that extends along the direction of propagation D (helical axis).

As mentioned above, angular momenta express the number of complete rotations made by the wavefront of the electromagnetic waves respectively, per wavelength, while the rotation direction of the wavefront of each of the electromagnetic waves is expressed by the modulus and sign of its orbital angular momentum.

1 2 1 FIG. The receiving antennas R, R, . . . , RM are arranged on a receiving surface R, which inwe identify with a plane intersecting the propagation direction D of the electromagnetic waves and positioned at a distance Z with respect to a transmission source T of the electromagnetic waves themselves.

1 2 1 2 1 2 1 2 1 2 Preferably, the receiving antennas R, R, . . . . RM are arranged in correspondence with a plurality of points r, r, . . . , rM belonging to the reception plane R and suitably positioned to use each of the observation sectors Sr, Sr, . . . , Srp corresponding, at least in pairs, to the wavefront sectors S, S, . . . , Sp composing the electromagnetic waves W, W, . . . , WK.

1 2 1 2 Preferably, the receiving antennas R, R, . . . , RM are positioned along at least one circumference or closed curve lying on R and centered on the propagation direction D of electromagnetic waves W, W, . . . , Wk.

1 2 The receiving antennas R, R, . . . , RM are preferably arranged on one or more circumferences or closed curves on the receiving plane R.

The number M of receiving antennas may vary as needed.

1 2 The number p of the sectors of each of the electromagnetic waves W, W, . . . , Wk can advantageously vary according to each emitted wave.

Preferably, M is an even number greater than or equal to two.

1 2 The reception plane R is preferably arranged in such a way as to be substantially orthogonal to the propagation direction D of the electromagnetic waves W, W, . . . , Wk.

3 103 20 1 2 The receiving device Rx,includes the discrimination means, e.g. electronic means, operationally associated with the receiving antennas R, R, . . . , RM.

20 The discrimination meansmay include any type of analog or digital circuit, as required.

20 1 2 1 The discrimination meansare suited to perform, in correspondence with the observation sectors Sr, Sr, . . . , Srp, amplitude and phase measurements of the electromagnetic field on the receiving plane R, in order to acquire the first DATAdata.

20 1 1 2 2 1 2 The discrimination meansare also suited to process the DATAdata obtained from the above-mentioned amplitude and phase measurements of the electromagnetic field ER, to separate the OAM channels associated with waves W, W, . . . . Wk, and to derive the DATAdata, to subdivide and identify each OAM carrier in each of the sectors Sr, Sr, . . . , Srp.

20 2 3 1 101 The discrimination meansare also able to further process the DATAdata thus obtained, in order to obtain third DATAdata by decoding each generic channel obtained by multiplying with analog or digital Chx, x, techniques the OAM data channel in the corresponding sector Sj of the generic OAM electromagnetic wave Wq, 1≤q≤k, for example in such a way that the final output signal from the Rx receiving device of apparatus,contains one and only one of said data channels.

20 1 2 1 2 Preferably, the discrimination meansreceive from each of the receiving antennas R, R, . . . , RM a receiving signal detected at one of the observation points r, r, . . . , rM.

1 2 1 2 20 2 By processing the DATAmeasurement data, indicative of the amplitude of the resulting electromagnetic field ER, on the receiving plane R, it is therefore possible to recognize the function that expresses the distribution of the amplitude electromagnetic field, on the receiving plane R, and thus obtain the DATAdata, indicative of the difference between the angular momenta of the electromagnetic waves W, W, . . . , Wk and their separation in reception. As explained above, the discrimination meansare able to acquire the DATAdata, indicative of the difference between the various OAM waves.

Preferably, as mentioned above, multiple channels can be associated with each OAM wave by independently modulating non-overlapping sectors of the wavefront.

3 103 20 In the receiving device Rx,, the acquisition of data transmitted through data channel C can be advantageously carried out thanks to appropriate decoding means (not illustrated), known type, even of a operationally associated with or integrated to/in the discrimination means.

1 2 1 2 3 4 1 2 1 FIG. Preferably, the receiving antennas R, R, . . . . RM are able to receive multiple electromagnetic waves W, W, W, W() in the wavefront sectors taken as example, S, S.

1 2 Preferably, the receiving antennas R, R, . . . , RM are movable on the receiving surface R as required.

1 2 1 2 1 2 The position of the observation points r, r, . . . , rM on the receiving surface R can thus vary as needed, in order to optimize the reception of the superimposed electromagnetic waves W, W, . . . , Wk. Preferably, the observation points r, r, . . . , rM are located in a neighborhood of the points of maximum of the modulus of the electromagnetic field ER.

1 2 The receiving antennas R, R, . . . , RM may consist of dipoles, paraboloids, or other structures of known type. Metamaterials and/or plasmonic materials can be advantageously used for their realization.

The number N of receiving antennas can vary as needed. Preferably, that number N is an even number greater than or equal to two.

In general, in the use of the remote radio link made by the present invention, the following steps can be performed:

Activating sections of the transmitting antenna in order to transmit an analog or digital communication channel in a well-established direction obtained by appropriate analog or digital modulation.

Activating said sections of the transmitting antenna so that only the receiving station is illuminated, and preferably transmitting a jamming modulation in the remaining directions.

Directing the transmission with an active feedback method in order to optimize the transmission of information to the recipient.

1 1 2 Receiving at least one of the electromagnetic waves W, with orbital angular momentum OAM=11, in correspondence with a receiving surface R, intersecting the propagation direction D, or alternatively, in the directions orthogonal to D, following an anamorphic transformation of affine homology of the wavefront, and positioned at a distance with respect to at least one source T of the electromagnetic waves W, W, . . . , Wk.

1 1 2 1 2 Carrying out amplitude and phase measurements of the electromagnetic field in order to acquire the first DATAdata indicative of the amplitude and phase distributions of the electromagnetic field ER resulting from the superimposition of electromagnetic waves W, W, . . . , Wk, in correspondence with said observation points r, r, . . . , rM.

1 2 1 2 Processing the first DATAdata to obtain the second DATAdata that allow the separation of the electromagnetic waves W, W, Wk into carrier signals for each chosen wavefront sector S.

2 3 Preferably, it is also possible to process the second DATAdata in order to obtain third DATAdata that make it possible to discriminate, if present, multiplexed data transmission channels in the various sectors, S.

1 2 identifying, on the receiving surfaces R, the points of maximum and minimum of the electromagnetic field ER resulting from the superimposition of the electromagnetic waves W, W, . . . , Wk; 1 2 identifying the observation points r, r, . . . , rM according to the number and position of said points of minimum in the various wavefront sectors S; merging the channels of each wavefront sector to increase the data transfer capacity of a single OAM wave; associating one or more different users to each of the wavefront sectors S for single or broadcast data transmission. Preferably, the method, according to the invention, also includes the steps of:

It has been seen in practice that the apparatus and the method, according to the invention, allow to solve the drawbacks described in the known art, achieving the set goals by associating multiple channels and multiple users to the same single OAM value.

The apparatus and the method, according to the invention, provide for simple amplitude and phase measurements of the electromagnetic field to detect this identifying characteristic quantity in the chosen sectors of the wavefront.

The apparatus and the method, according to the invention, are thus relatively simple and inexpensive to implement in practice, compared to the telecommunication systems and methods of the known art.

The apparatus and the method, according to the invention, involve the use of receiving/transmitting antennas with very simple geometries and easy to use in practice.

In understanding the purpose of this invention, the term “comprehending” and its derivatives, as used herein, are understood to be open-ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or phases, but do not exclude the presence of other undeclared features, elements, components, groups, integers, and/or phases. The above also applies to words that have similar meanings such as the terms “including”, “having” and their derivatives. In addition, the terms “part”, “section”, “portion”, “member” or “element” when used in the singular may have the double meaning of a single part or a plurality of parts. As used here to describe the form(s) of actuation above, the following directional terms “forward,” “backward,” “above,” “down,” “vertical,” “horizontal,” “below,” and “transverse,” as well as any other similar directional term, refer to the actuation form described in operative position. Finally, grade terms such as “substantially,” “about,” and “approximately” as used here mean a reasonable amount of deviation of the modified term such that the final result is not significantly changed.

While only selected embodiments have been chosen to illustrate the present invention, it will be clear to experts in the field from this description that various modifications and variations can be made without straying from the scope of the invention as defined in the attached claims. For example, the size, shape, position, or orientation of the various components can be changed as needed and/or desired. Components shown that are directly connected or in contact with each other may have intermediate structures arranged between them. The functions of one element can be performed by two and vice versa. The structures and functions of f one form of realization can be adopted into another form of realization. It is not necessary for all the benefits to be present in a particular form of realization at the same time. Any feature that is original compared to the known technique, alone or in combination with other features, should also be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts incorporated by those features. Therefore, the foregoing descriptions of the embodiments under the present invention are provided for illustrative purposes only and not for the purpose of limiting the invention as defined by the attached claims and their equivalents.